Which form to use - VA Form 21-526 or VA Form 21-534

This is my first post so I hope I'm doing this correctly!! My 82 year-old mother is applying for the Aid and Attendance benefit since she has just moved into an Assisted Living facility. She is the surviving spouse of a deceased WW2 veteran (my father). She herself has never served in the military. I am currently helping her compile all the information and paperwork needed but am unsure which form we should be using - VA 21-526 and/or VA 21-534.